Conventionally, as a material for a cutting tool, there has been employed a WC based cemented carbide obtained by sintering WC (tungsten carbide) particles by Co (cobalt).
A cutting tool has a cutting edge, which usually has a high temperature due to heat resulting from deformation and friction when cutting a workpiece. Hence, the cutting tool needs to be formed of a material (base material) capable of maintaining sufficient hardness and strength even when it has a high temperature. Conventionally, in order to improve the wear resistance of the cutting tool when it has a high temperature, high-temperature hardness thereof is improved by introducing an element such as Ti, Nb, Ta, or Zr into a cemented carbide, which serves as the material thereof. Alternatively, a surface of the tool is coated with a ceramics film high in high-temperature hardness, such as alumina, titanium carbide, or the like. Meanwhile, in order to decrease the temperature of the cutting tool itself or the workpiece itself, it is effective to use a cutting fluid. Japanese Patent Laying-Open No. 08-225877 (hereinafter, referred to as “Patent Literature 1”) discloses a sintered alloy having a surface provided with a layer having many WC particles of high thermal conductivity in order to increase the thermal conductivity of the surface of the alloy. A surface of an alloy is likely to have a high temperature.